Circuit-closer.



C. SHELDON.

CIRCUIT CLOSER. APPLICATION FILED APR. 8. 1915.

1,239,830. Patent edSept. 11, 1917.

W 6V4; Q2224 NESSES MW W Z: ATTORNEY UNITED STATES PATENT OFFICE.

CORLISS SHELDON, OF SARATOGA SPRINGS, NEW YORK.

CIRCUIT-CLOSER.

Application filed April 8, 1915.

To all whom it may concern:

Be it known that I, CoRLrss SHELDON, a citizen of the United States of America, and a resident of Saratoga Springs, county of Saratoga, and State of New York, have invented certain new and useful Improvements in Circuit-Closers, of which the following is a specification, reference being had to the accompanying drawings, forming a part thereof.

My invention relates to circuit closers and has special reference to such as depend upon the fusion of metal or other normally solid substances for automatically establishing an electric circuit.

One object of my invention is to provide a simple and durable device of the aforesaid character that shall be inexpensive in construction and reliable in operation.

Other objects and advantages of my invention will be set forth hereinafter, and in order that my invention may be fully understood I will now proceed to describe the same in the following specification and then point out the novel features thereof'in appended claims.

Referring to the drawings:

Figure 1 is an elevation in longitudinal section of a circuit closer constructed in accordance with my invention.

Several adjacent parts of the same structure ar shown in perspective in Fig. 2 separated to make their relative positions clear.

One of the conducting members is shown in detail on a larger scale in Fig. 3.

The circuit closer illustrated comprises a block 10 of insulating material, a pair of terminal screws 15 and 16, conducting members 17 and 18 and bodies 19 and 20 of fusible metal supported respectively by the members 17 and 18.

The block 10 has holes 11 and 12 near its respective ends, to adapt it to receive supporting screws 1 not shown), a central aperture 13 and a recess 14. The dimensions of the recess 14 are such that the members 17, 18 and 25 fit closely into it, and are held firmly against twisting or turning in the positions indicated in Fig. 1, the upper surface of the conducting member 17 being substantially flush with the top of the block. It is furthermore provided with holes on the opposite sides of the central aperture 13 through which the terminal screws 15 and 16 extend, as clearly shown in Fig. 1.

Specification of Letters Patent.

Patented Sept. 11, 191 *7.

Serial No. 19,892.

The conducting members 17 and 18 are similar to each other and as clearly shown in Figs. 2 and 3 have cupshaped indentations 21 in which the bodies of fusible metal 19 or 20 are disposed. The fusible metal may be solder or some other suitable current conducting substance which is cast or set in the cup.

The conducting member 18 has a hole 22 through which the bolt 16 extends when it is fitted into one end of the recess 14, with its cupshaped indentation extending into the central aperture 13. It is clamped in pomtion by a nut 23. The terminal screw 16 is further provided with a nut 24: so that a conducting wire may be clamped readily between the nuts 24 and 23 in the usual manner.

The insulating washer 25 which resembles one of the conducting members in shape, except that it has an aperture 26 instead of a cupshaped indentation, is fitted in the opposite end or" the recess 1% with the terminal screw 15 extending through it, the aperture 26 being opposite the opening of the cup in the member 18.

The member 17 is also fitted into the recess H above the insulating washer and is clamped in position by a nut 27 on the terminal screw 15. Tiiis screw is also provided with a nut 28 corresponding to the nut of the other terminal. The arrangement of parts is such that the two cups 21 are opposite each other, the two conducting members being separated electrically by means of the washer exce t opposite the aperture 26 therein. where the two bodies of fusible metal are only separated by an air space equal in thickness to the thickness of the washer.

In case the device is subjected to heat from any cause suflicient to soften the fusible metal. the two bodies will immediately flow together and will complete an electric circuit between the terminals. It is particularly sensitive to temperature changes because of the fa ct that the members 17 and 18 are made of thin metal and as the cup-like portions are stamped in them, its metal is still thinner over the fusible metal which is contained in these portions. As the space between these fusible parts is entirely inclosed. the device is operative in any posi tion in which it maybe placed. Furthermore, on account of the fact that this space is inclosed, there is no opportunity for for cign matter to get in between the bodies of fusible metal to form a short circuit between them.

The block 10 is preferably notched as shown at 30 in order to provide an open transverse air space between the indented portions of the conducting members and the surface or wall to which the block is secured.

The structure above described is, of course, adapted for a wide Variety of uses but has the special advantage of being well adapted for use with small current apparatus since it can be manufactured in very small sizes at low cost.

The above described invention is particularly well adapted for use as an automatic fire alarm in connection with annunciators, telephones, electric bells or other audible or visible signals to automatically indicate by the signal device whenever a fire occurs in any portion of the building or other structure, in which my circuit closer is installed, and also the precise room or place where said fire is located. I have not illustrated any signal system of the aforesaid character because such systems are well known and furthermore my invention may be used for various purposes.

The operation of my invention when used in connection with a fire alarm system is apparent. WVhen a fire occurs in a room in which my circuit closer is placed, the heat from the fire melts the solder or other substance which is fusible at a low temperature, thereby causing the circuit to close, and thereby causing the annunciator, telephone, bell or other audible or visible signal with which it is connected to be continuously 0perated, giving warning by the mere fact of its continuance that a fire exists at the point indicated.

What I claim is:

1. A circuit closer comprising a pair of like interchangeable conductors having flat surfaces and having cups formed therein opposite each other and containing fusible conducting material filling said cups to the planes of said flat surfaces, and a spacer of insulating material between the conductors and having an aperture to provide a communicating passage between the cups.

2. A circuit closer comprising a pair of like interchangeable conductors having fiat surfaces and having cups formed therein, arranged with their openings opposite each other and containing fusible conducting material filling said cups to the planes of said flat surfaces, and a spacer of insulating material between the conductors and having an aperture to provide an inclosed communicating passage between the cups.

3. A circuit closer comprising an insulating block having a central aperture, a pair of terminals secured to the block at a fixed distance apart, flat conducting members extending adjacent to each other across the central aperture of the block and having opposite cupshaped indentations filled with fusible material, and means for spacing the conducting members apart.

4. A circuit closer comprising an insulating block having a central aperture, a air of terminals secured to the block at a xed distance apart, flat conducting members, extending adjacent to each other across the central aperture of the block and having opposite cup-shaped indentations filled with fusible material, and a spacer of insulating material having an aperture to provide a. communicating passage between the cups through which the fusible material may flow when softened.

5. A circuit closer comprising an insulating block having a central aperture, a air of terminals secured to the block at a xed distance apart, conducting members of thin flat metal, extending adjacent to each other across the central aperture of the block and having opposite cupshaped indentations pressed therein and filled with fusible conducting material, and a spacer of insulating material having an aperture to provide an inclosed communicating passage between the cups into which the fusible material may flow when softened.

6. A circuit closer comprising an insulating block having a pair of spaced terminal posts, a pair of interchangeable conductors each having a cup formed therein near one end and containing fusible conducting material, said conductors being secured to the respective terminal posts and extending with their cups opposite each other, and a spacer of'insulating material between the conductors having an aperture to provide a communicating passage between the cups.

In witness whereof, I have hereunto set my hand this 6th day of April, 1915.

CORLISS SHELDON.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents. Washington, D. 0. 

